<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        body{
            display: flex;
            justify-content: center;
            align-items: center;
        }
        .box{
            width: 200px;
            height: 200px;
            background-color: pink;
            transition: all(0.3s);
        }
        .box::before{
            content: "fdgfh";
            width: 20px;
            height: 20px;
            background-color: yellow;
            background-image: url("./img.jpg");
        }
        .box::after{
            content: "fdgfh";
            width: 20px;
            height: 20px;
            background-color: purple;
        }
        .box:hover{
            background-color: skyblue;
            margin-top: 100px;
        }
        .box:active{
            background-color: red;
        }
      
        
    </style>
</head>
<body>
    <div class="box">规范和环境更加可靠</div>

    
</body>
</html>